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<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        //创建Symbol
        let s = Symbol();
        console.log(s, typeof s);
        let s2 = Symbol('尚硅谷');
        let s3 = Symbol('尚硅谷');
        console.log(s2 === s3); //false

        //Symbol.for 创建  这个Symbol是一个函数对象
        let s4 = Symbol.for('尚硅谷');
        let s5 = Symbol.for('尚硅谷');
        console.log(s4 === s5); //true

        //不能与其他数据进行运算

        // undefined
        // srting symbol
        // object
        // null number
        // boolean
    </script>
</body>

</html>